1. Field of the Invention
This invention relates to industrial robot systems, and more particularly to a measure which is taken when an industrial robot system is stopped unintentionally.
2. Prior Art
As-disclosed by Japanese Patent Application (OPI) No. 88301/1986, an industrial robot system is available which is provided with earthquake control means operating on an earthquake detector at the occurrence of an earthquake.
In the industrial robot system, an earthquake control operation is carried out to stop the operation of the industrial robot or retract it from line when an earthquake occurs.
The above-described conventional industrial robot system suffers from the following problem: When the industrial robot system is stopped unintentionally, the actual condition of the industrial robot or its peripheral materials such as work materials is often deviated from that required by the operating program for instance because it is manually moved after the unintentional stop. Hence, when the industrial robot system is started again, troubles may occur, for instance the industrial robot may perform unexpected operations to damage the peripheral equipment.